"A ship engine failed, no one could fix it. Then they brought in a man with 40 yrs. on the job. He inspected the engine carefully, top to bottom. After looking things over, the guy reached into his bag and pulled out a small hammer. He gently tapped something. Instantly, the engine lurched into life. The engine was fixed! 7 Days later the owners got his bill for 10k. 'What?!' the owners said 'You hardly did anything. Send us an itemized bill. The reply simply said Tapping with a hammer - $2 Knowing where to tap? - $9,998 Don't Ever Underestimate Experience."